1. Technical Field
Embodiments of the present invention relate to an illumination apparatus. More particularly, embodiments of the present invention relate to an illumination apparatus with a lens structure.
2. Description of Related Art
The emission angle of a typical light emitting diode (LED) is constant, e.g., 120 degrees. To meet demands on optical characteristics of various illumination modules, a secondary optical lens is usually applied to cover the LED to modify the illumination distribution of the LED.
Generally, during the manufacturing process, the LED is mounted on the substrate by the surface mount technology (SMT), and then, the LED is fastened thereon during a first heat treatment process like a reflow process. After the LED is fastened, the secondary optical lens can be disposed on the substrate with glue and covers the LED. The glue can be cured by a second heat treatment process, such as a roasting process.
Because the LED requires solder to be fastened on the substrate, and the melting temperature of the solder is higher than the temperature of the second heat treatment of the secondary optical lens, the typical lens made of the plastic material tends to deform or deteriorate.
In view of the foregoing, the LED and the secondary optical lens currently cannot be formed within one single heat treatment process. It is inevitable that two heat treatment processes are required to mount the LED and the secondary optical lens on the substrate, which raises the manufacture cost and may influence the optical characteristic of the LED.